Monolithic linear variable filter and method of manufacture
US5872655A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 5, 1997 |
| Grant date | Feb 16, 1999 |
| Priority date | — |
| Expiry date | May 5, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B1/10
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A process suitable for forming multi-layer (up to at least several hundred layers) monotonic/linear variable/wedge filter coatings on a single substrate surface and for forming monolithic filter assemblies which incorporate such filters, is disclosed along with the designs for such filters. The monolithic process uses radially variable filter fabrication techniques in combination with ion-assisted deposition to form stress controlled, radially variable filter coatings of the desired varied optical profile, preferably using high and low index materials stich as tantala and silica. Stress is minimized by balancing the amount of ion assist and the coating rate. Slices are cut radially from the substrate to form quasi-linear variable filters. Other coatings such as, but not limited to, a wide band hot mirror can be formed on the opposite surface of the substrate from the radially variable LVF method. The method forms complex multi-layer thick filters with high yields on a single substrate surface such that the filter is free of precession or sideways leakage of light between the parallel surfaces. Also disclosed is an optical filter having stacks arranged so that the magnitude of the c…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.